Wait. Something isn’t right here…

No clue where this is from, but something seems sort of off, no? I guess we should take the title literally. By the numbers… only.

I’m going to give the benefit of the doubt though, and assume this was just an honest mistake. Here’s my guess about what happened. A deadline was coming up quick, and a graphics editor put this together to get a feel for what the final design would look like. He then saved it as a different file, and then went to work. Except when it came time to send the file to the printers, the editor sent the wrong file. Actually, now that I think about it, I’m surprised this doesn’t happen more often.

Does any reasonable charting software have a default height for white and red bars?! Or ask for the proportions to be entered into text-boxes above the bar? Was this person going to manually adjust bar heights?!

As someone who teaches future science teachers and knows exactly how little some of our undergraduates understand science and data, I’m not surprised and I don’t think it was a mistake. This was an easy way to show the differences and all they were worried about was the overall message. It could have been cobbled together by anyone.

The even sadder thing is that the overall message is really important, but the message is weakened by such a presentation. Whether it comes to substance use, bullying in schools, relationships with parents, etc… kids and college students typically think that these things occur much more often than they actually do.

Ended up writing a long blog post about this chart, not because of the error necessarily, but what the best way to show this information would be – bars, dealing with axes scales, pie charts (yes, really), bubble charts, and the initial study design..